Word Origin & History

thick O.E. þicce "not thin, dense," from P.Gmc. *theku-, *thekwia- (cf. O.S. thikki, O.H.G. dicchi, Ger. dick, O.N. þykkr, O.Fris. thikke), from PIE *tegu- "thick" (cf. Gaelic tiugh). Secondary O.E. sense of "close together" is preserved in thickset and proverbial phrase thick as thieves (1833). Meaning "stupid" is first recorded 1597. Phrase thick and thin is in Chaucer (c.1386); thick-skinned is attested from 1545; in fig. sense from 1602. Verb thicken is first recorded c.1425 (trans.), 1598 (intrans.); an earlier verb was O.E. þiccian. To be in the thick of some action, etc., ..."to be at the most intense moment" is from 1681, from a M.E. noun sense.